To suit tapered forks If you are running a 1 1/8'' fork you will need to purchase the Works Components reducer crown. - this headset comes as standard with a crown race to suit tapered forks Upper cup Stack height: 11mm - Total upper stack height including bearing cover: 16mm Lower cup Stack height: 14mm Upper Bearing: 41mm OD, 45 x 45 Degree AC sealed bearing Lower Bearing: 52mm OD, 45 x 45 Degree AC sealed bearing Upper cup insertion depth: 9mm Lower cup insertion depth: 10.5mm Split type 7075-T6 aluminium crown race for simple, tool free installation Headset comes complete with top-cap (star-nut included), bearings and crown race - all parts required for fitment